Champions

Seeing as lux, miss fortune, and the others got their Ultimate skin, I ask this question, will every champion get an ultimate skin at some point, or just only a certain selected few? I've already thought of ultimate skins for at least a decent amount of the champions and every since the Gun Goddess Miss Fortune ( Butt Goddess Miss Fortune as some call her...) I just can't help but constantly think about the other champions, even the ones that hardly get noticed. (I.e. jayce, kassadin, lissandra, sejuani, Anivia, kindred, Kled, rumble, Annie, twitch, brand, e.t.c.) will they get ultimate skins at some point in the future? I honestly hope so. ( Despite my hatred of some of them..) also, legendary skin champions, I noticed that champions that got a ultimate skin, didn't have a legendary skin. Now yes some of the champions have neither, but I noticed so far, that the ultimate skin champions didn't have a legendary skin... Does that mean that if the champion has a legendary skin already, that means they can't have an ultimate skin? Or is this just a coincidence? I honestly don't know if they have some system towards these events, or if it's just through some strange decision-making technique (something probably dumb like selecting a few random champions and blindly throwing darts at it.), Either way, it's ultimate skin ideas like Miss Fortune and lux they makes me wish I could show them some of the skin ideas I had drawn up and wondered if they would like them. Anyway, I can't wait to see what the next ultimate skin will be for.